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Biomedical subjects

A Giannetti

Publications and source records attributed to A Giannetti.

At least 91 records · Page 5Linked to original sources
PubMed1992

Substance P levels are decreased in lesional skin of atopic dermatitis.

There is increasing evidence that neuropeptides (NP) such as substance P (SP) and vasoactive intestinal polypeptide (VIP) are involved in the pathogenesis of atopic dermatitis (AD). Vasoactive intestinal polypeptide levels were found to be significantly elevated in lesional skin of AD as compared to controls. We evaluated by radioimmunoassay the SP content in whole skin homogenates from chronic lichenified lesions of patients with AD. The levels of SP were significantly decreased in lesional skin from AD patients as compared to control skin (0.25 +/- 0.03 vs. 0.97 +/- 0.24 pmol/g tissue, p < 0.01). The diminished SP levels as opposed to increased VIP concentrations could be consistent with different roles of these NP as modulatory agents in the mechanisms associated with AD.

Adolescent↗
PubMed1992

Vasoactive intestinal polypeptide and substance P in the pathogenesis of atopic dermatitis.

Neurogenic components are probably involved in the pathogenesis of atopic dermatitis (AD) and several neuropeptides have been implicated in the mechanisms underlying this disease. The aim of the present study was to evaluate by radio-immunoassay (RIA), the vasoactive intestinal polypeptide (VIP) and substance P (SP) content in whole-skin homogenates of AD lesions. RIA was performed using an antiserum, AH78, recognizing the carboxy-terminal fragment VIP (22-28) and a polyclonal antiserum directed against SP. VIP levels were markedly increased in lesional AD skin (5.62 +/- 1.25 pmol/g tissue) vis-à-vis controls (0.43 +/- 0.08 pmol/g tissue), whereas SP levels were significantly lower in lesional skin (0.25 +/- 0.03 pmol/g tissue) than in normal skin (0.97 +/- 0.24 pmol/g tissue). The results confirm that VIP and SP are relevant to the pathogenesis of AD and their imbalance might reflect diverse roles of these NP in the modulation of AD lesion.

Adolescent↗
PubMed1992

Cutaneous innervation in chronic renal failure patients. An immunohistochemical study.

Most chronic renal failure patients suffer from generalized pruritus. An involvement of cutaneous nerve terminals in the pathogenesis of uremic pruritus has been suggested. Skin specimens from 24 uremic patients and 10 healthy subjects were processed with an indirect immunofluorescence method to investigate the presence and distribution of a number of neuronal markers and neuropeptides. No difference was found between the two groups in the distribution pattern of the positive nerve fibres. However, a reduction in the total number of skin nerve terminals in the uremic patients was detected. No correlation could be found between the immunohistochemical findings and the clinical features. Our results suggest that the skin innervation is altered in most chronic renal failure patients, possibly as a consequence of neuropathy.

Adult↗
PubMed1992

Positive patch tests to whole mite culture and purified mite extracts in patients with atopic dermatitis, asthma, and rhinitis.

Patch tests with Dermatophagoides were carried out by different authors on patients with atopic dermatitis (AD) employing methods varying both in the type of allergen and in the way of performing the test. In order to examine and compare different methods and various allergenic materials and to define better the indications for this test, we performed patch tests with whole mite culture or purified mite extracts on 72 patients with AD, 40 subjects with mucosal atopy, and 32 healthy volunteers, employing different techniques of application. Positive results were obtained in 51.5% of patients with AD with specific IgE to Dermatophagoides, in 43.6% of patients with AD without this specific IgE and in 40% of subjects affected by mucosal atopy and having specific IgE to Dermatophagoides. From a technical point of view the simple application of the allergenic material on healthy skin gave the best results. Our data show that patch tests with Dermatophagoides extracts could contribute to a better immunoallergologic characterization both of patients with AD and patients with mucosal atopy.

Adolescent↗
PubMed1992

Treatment of leg ulcers with cryopreserved allogeneic cultured epithelium. A multicenter study.

BACKGROUND: In the past few years, several authors have described the usefulness of cultured allogeneic epidermal sheets in promoting wound healing of burns, leg ulcers, and donor sites. This study reports clinical results obtained by different departments in the treatment of chronic leg ulcers by cryopreserved cultured allogeneic epithelium. The freezing procedure and the assessment of viability of the cryopreserved epithelium are also described. A total of 30 ulcers were treated using 138 cryopreserved allografts. OBSERVATIONS: Twenty ulcers (66.6%) healed completely within 12 weeks. Four ulcers showed a 30% to 84.4% reduction in size by 3 weeks but did not heal completely; the remaining six ulcers did not show any improvement. A strong stimulation of granulation tissue formation and of reepithelialization from the wound edge were observed. RESULTS: The results indicate that frozen cultured epidermis, stored in a skin bank, is a valid and generally applicable alternative therapy for the treatment of chronic ulcers.

Aged↗
PubMed1991

Skin levels of vasoactive intestinal polypeptide in atopic dermatitis.

Atopic dermatitis (AD) can be exacerbated by various factors, including emotional stress, scratching and sweating. The aim of the present study was to evaluate the hypothesis that the inflammatory reaction in AD is also neurogenic. For this purpose, the levels of vasoactive intestinal polypeptide were measured radioimmunologically in whole-tissue homogenates of lesional skin of 13 patients with atopic dermatitis. Radioimmunoassay was performed using an antiserum, AH78, recognizing the carboxy-terminal fragment vasoactive intestinal polypeptide (22-28). Vasoactive intestinal polypeptide immunoreactivity was detected in relatively low amounts in control skin (0.428 +/- 0.08 pmol/g tissue), whereas a marked increase in the peptide was observed in lesional skin of patients with atopic dermatitis (5.62 +/- 1.25 pmol/g tissue). These results seem to suggest that vasoactive intestinal polypeptide could have a pathogenetic relevance in skin lesions of atopic dermatitis.

Adolescent↗
PubMed1991

Detection of HIV-1 in epidermal Langerhans cells of HIV-infected patients using the polymerase chain reaction.

Langerhans cells (LC) are bone marrow-derived, HLA-DR+, CD1a+, dendritic antigen-presenting cells found in stratified squamous epithelia. Within resident epidermal cells (EC), LC are the only cells expressing the CD4 antigen and are, therefore, a possible target for human immunodeficiency virus (HIV) infection. To date, conflicting results have been reported on the in vivo infection of LC by HIV. The aim of the present study was to investigate the presence of HIV-1 proviral DNA in epidermal LC of HIV-1-infected patients. EC suspensions were prepared from clinically normal skin of nine seropositive patients. Purified LC and LC-depleted EC were obtained by immunomagnetic separation and analyzed for the presence of HIV-1 proviral DNA by the polymerase chain reaction using primer pairs from different conserved regions (env and gag) of the HIV-1 genome. HIV-1 proviral DNA was detected in LC from seven of nine patients. LC-depleted EC fractions from the same nine patients were all negative, with the exception of one case. Altogether these results demonstrate that epidermal LC are infected by HIV-1 and constitute the only resident cell type in the epidermis harboring the virus. Further studies are, however, needed to demonstrate HIV replication in LC and to elucidate the functional role of LC in this infection.

Adult↗
PubMed1991

Immunohistochemistry of cutaneous graft-versus-host disease after allogeneic bone marrow transplantation.

Graft-versus-host disease (GVHD) is an immunologically mediated disease occurring most frequently after allogeneic bone marrow transplantation. The aim of this study was to evaluate the contribution of immunohistochemistry in the diagnosis of cutaneous GVHD. Patients transplanted for either leukemia or beta-thalassemia were included in the study. Skin lesions of acute and chronic GVHD were examined both by direct immunofluorescence to detect immunoglobulin deposits and by an avidin-biotin-peroxidase complex technique to evaluate the inflammatory cell infiltrate. Epidermal and dermal fluorescent bodies (IgG and IgM) were frequently found in both acute and chronic GVHD. Most of the infiltrating cells were CD3+ T lymphocytes, with CD8+ cells representing the major cell population invading the epidermis both in acute GVHD and in chronic lichenoid GVHD. A small proportion of the dermal cells were CD14+ macrophages; no B cells were detected. HLA-DR, but not HLA-DQ antigens, were variably expressed by keratinocytes in all cases of acute GVHD and in chronic lichenoid GVHD. KL-1, a monoclonal antikeratin antibody specific for the 56.5 KD acidic polypeptide usually present in suprabasal keratinocytes, stained all epidermal layers, including the basal layer. Langerhans cells were dramatically reduced in number in the epidermis of both acute and chronic lichenoid GVHD. It is concluded that immunohistologic analysis may be supportive in the diagnosis of acute and early chronic lichenoid cutaneous GVHD.

Acute Disease↗
PubMed1991

VLA protein expression on epidermal cells (keratinocytes, Langerhans cells, melanocytes): a light and electron microscopic immunohistochemical study.

The very late antigens, or VLA proteins, are a family of cell surface heterodimers (alpha 1-b beta 1) that mediate cell adhesion to specific components of the extracellular matrix (collagens, fibronectin, laminin). In normal human epidermis, the common VLA beta 1 subunit is expressed on basal keratinocytes (BK). Langerhans cells (LC) and melanocytes. By means of light and electron microscopic immunostaining procedures, we have investigated the distribution of VLA alpha 1,2,3,4,6 subunits on normal human adult and foetal epidermal cells. alpha 1 antigen expression was not observed on any epidermal cell type. Both during foetal development and in adult epidermis, alpha 2 and alpha 3 were strongly expressed on the cell membrane BK, while alpha 6 was mainly expressed at their dermal pole. These different patterns of distribution suggest that the alpha 6 subunit may mediate BK anchorage to the basement membrane zone, while the alpha 2 and alpha 3 subunits may also be involved in intracellular adhesion. Moreover, with immunoelectron microscopy, LC were seen to be weakly alpha 5 and alpha 6 positive and melanocytes were alpha 3 and alpha 6 positive. Thus, VLA proteins are expressed by epidermal cells in a cell-type-specific pattern that could be related to particular functional roles of these proteins.

Adult↗
PubMed1991

Ultrasound B scanning with image analysis for assessment of allergic patch test reactions.

Assessment of patch test results has been performed visually and using ultrasound in the B mode. A positive test site has a typical ultrasonographic appearance, presenting a uniform hypoechogenic area in the dermis. In this zone, the mean amplitude of ultrasound reflection peaks decreases, and the extension of this area increases, together with the intensity of the eczematous reaction. A close correlation has been shown between visual scoring, amplitude decrease and surface increase of the hypoechogenic area. This technique seems to provide a reproducible system for the evaluation of patch tests.

Adolescent↗
PubMed1990

[Epidemiologic and diagnostic observations on hemorrhage of the upper gastroenteric tract].

Acute upper gastrointestinal (GI) bleeding causes, according to the authors' experience, 1.65% of all annual hospitalizations. Mortality rate among high risk patients is about 20% and cirrhotic patients have a particularly poor outcome (70% of deaths caused by gastrointestinal hemorrhage). Endoscopy has been performed in 329 cases to identify the active site of bleeding (7.22% of 4791 "EGDS" performed from 1984 to 1988). In this retrospective study gastric and duodenal peptic diseases, have been observed more frequently than esophageal varices ruptures (11.8%) and in 25% of patients Gl bleeding was associated with the use of potentially dangerous drugs (NSAID and/or Steroids). A prompt endoscopy is fundamental to recognize the etiology and for a better management of the patient; unfortunately, even if improvements have been obtained in the diagnosis and therapy, the mortality caused by gastrointestinal hemorrhage is not significantly reduced.

Acute Disease↗
PubMed1990

Epidermal growth factor and transferrin receptor expression in human embryonic and fetal epidermal cells.

Epidermal growth factor receptors (EGFR) and transferrin receptors (TFR) are known to be involved in cell proliferation and to be expressed in normal human epidermis. To date little is known about EGFR and TRF expression in human skin during embryonic and fetal development. In the present work, we studied skin specimens from 30 aborted embryos and fetuses ranging from 7 to 31 weeks estimated gestational age. Monoclonal antibodies to EGFR and TFR were applied on frozen skin sections using an amplification biotin-streptavidin-fluorescein technique. TFR was faintly expressed on epidermal basal cells throughout embryonic and fetal development, as it is in adult epidermis. Up to week 12, EGFR was uniformly expressed on cells of the basal, intermediate and periderm cell layers. From the midfetal period onwards, the suprabasal cell layers showed a decreased staining compared with the basal layer. During the third trimester the cornified cell layer was completely negative. The hair germ and heir peg cells were positive. Later, the outer root sheath and hair bulb remained labelled, with less staining of the hair cone. The sebaceous and eccrine sweat glands were also labelled. These results suggest that in embryonic and fetal epidermis, TFR expression is not correlated with cellular proliferation, whereas EGFR appear to be associated with proliferating and undifferentiated cells.

Adult↗
PubMed1990

Oral hairy leukoplakia in AIDS patients: an ultrastructural study.

Hairy leukoplakia is a specific oral lesion associated with the opportunistic development of Epstein-Barr virus in the oral epithelium. It is now considered to be an early sign of HIV-induced immunosuppression. Four cases of oral hairy leukoplakia (OHL) from the lateral borders of the tongue of male AIDS patients were investigated by transmission electron microscopy. At the ultrastructural level, herpes-like viral particles were detected in the oral lesions of all cases. Indirect immunofluorescence performed on two cases showed the presence of EBV antigens in the nuclei and the cytoplasm of the infected epithelial cells. None of the specimens contained ultrastructural evidence of human papillomaviruses.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Neuropeptides in skin from patients with atopic dermatitis: an immunohistochemical study.

The distribution and localization of several neuropeptides were investigated in the lichenified lesions of 11 patients with atopic dermatitis using indirect immunofluorescence. Substance P-positive nerve fibres were observed in most of the cases of atopic dermatitis, but not in normal controls. Somatostatin immunoreactive nerves were not found in the skin of atopic dermatitis, whereas a normal pattern of immunoreactivity could be detected in most of the healthy subjects. Neuropeptide Y-positive dendritic epidermal cells were observed in lesional skin from patients with atopic dermatitis, but not in controls. Calcitonin gene-related peptide and vasoactive intestinal polypeptide immunoreactivity in patients with atopic dermatitis did not differ from that in healthy subjects. With galanin antiserum a diffuse intracellular staining was observed in the epidermis of both atopic patients and controls, while no positive staining was found with either neurotensin or neurokinin A antibodies in either group. These findings suggest a possible involvement of some neuropeptides in the pathomechanisms of atopic dermatitis.

Adolescent↗
PubMed1990

Sexually transmitted diseases in Italy: clinical returns versus statutory notifications.

Sexually Transmitted Diseases (STD) surveillance has caught the attention of the Italian public health authorities during the past decades. The spread of HIV infection increased the awareness of the need for a better STD surveillance system. This paper reports a retrospective survey of STD clinics in Italy, intended to form an epidemiological base for further development of STD surveillance. The data for 1986-87 and 1988 on a predefined set of diseases, all of them sexually transmitted, were collected from 85 of 127 centres contacted. The data obtained offer the first national figures for some STD not included in the statutory notification list, such as chlamydial infection, herpes and genital warts, as well as HIV infections. Those data show an increase in time frequencies. For gonorrhoea and syphilis, it was possible to compare our data with statutory notifications, showing a large gap between notified and reported cases. This gap is not stable in time (increasing in time) or in geographical area (increasing from north to south).

Gonorrhea↗