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Biomedical subjects

S Moretti

Publications and source records attributed to S Moretti.

At least 73 records · Page 4Linked to original sources
PubMed1997

Fibrogenic cytokines in vulvar lichen sclerosus. An immunohistochemical study.

OBJECTIVE: To evaluate the expression of fibrogenic cytokines in lichen sclerosus (LS) infiltrate as compared with lichen planus (LP) infiltrate. STUDY DESIGN: Eight cases of vulvar LS (early stage, n = 3; well developed or old, n = 5) and 4 of vulvar LP were studied. Monoclonal antibodies directed against some of the major fibrogenic cytokines (IL-4, TGF-beta, IL-6) and against IFN-gamma, which inhibits collagen synthesis, were used per the alkaline phosphatase/anti-alkaline phosphatase technique on frozen sections. RESULTS: Staining for IL-4 revealed higher expression of fibrogenic cytokines (more than 50% infiltrating cells) in the LS infiltrate, mainly in early lesions, than in LP. Conversely, staining for IFN-gamma in LS was poor (less than 10% infiltrating cells), while strong positivity (more than 60% infiltrating cells) was found in LP. Staining for TGF-beta, a mediator of fibrosis in scleroderma, was similar in both LS and LP dermis. CONCLUSION: This study showed the immunohistochemical expression of fibrogenic cytokines in vulvar LS, with a different pattern as compared to that of LP. It is conceivable that dermal infiltrating cells actively participate, via cytokine production, in the pathogenesis of fibrosis in LS.

Adult↗
PubMed1997

Prolonged in vitro culture modifies the surface lipid composition of murine melanoma cell lines.

Lipid composition of two murine melanoma cell variants (B16, without malignant properties and B16-F10, with high metastatic activity), has been examined at different stages of growth. The aim of the work was to identify cell surface modifications due to the time length of in vitro culture, that could be one variable to consider when metastatic potential is studied. Some of the analyzed parameters (ganglioside- and glycoprotein-bound neuraminic acid, cholesterol, neutral glycolipids, phospholipids, triacylglycerols) undergo statistically significant variations at the various passages in B16-F10 line. Fatty acids composition of the phospholipidic fraction was changed only at the last observed passage (100) in B16 line. No one of the examined parameters justifies the ability of B16-F10 cells to invade distant districts and to originate new tumors. Probably detailed lipid analysis on cellular subfractions, as already performed in this study on total lipid extract of the whole cell, could be a valuable tool to identify differences related with metastatic potential.

Animals↗
PubMed1997

CD8 lymphocytes in HIV infection: helpful and harmful.

The part played by CD8 lymphocytes in the pathogenesis of human immunodeficiency virus infection (HIV) is much disputed and the relevant issue of the controversy ranges as to whether the functional activity of these cells is beneficial or detrimental to the host. Even though CD8 cells could efficiently suppress HIV replication through both major histocompatibility complex (MHC)-restricted cytotoxic killing of infected cells, particularly during primary infection, and HIV-suppressing soluble factors, there is evidence that tissue-infiltrating CD8 lymphocytes mediate injury in several organs of HIV-infected subjects. Furthermore, CD8 lymphocytes could contribute to the destruction of CD4 cells in vivo. Of note, the virus has the capability to escape the recognition by cytotoxic CD8 cells and the cytotoxic activity of CD8 cells and their counts decline with evolving HIV infection. Several mechanisms are proposed to explain this latter finding, including the direct in vivo infection of CD8 cells by the virus. It is likely that early during the course of HIV infection when viral loads are generally low an efficient CD8 cell response can control HIV replication whereas in subjects with evolving disease, who have very high viral loads, CD8 lymphocytes remove essential components of the immune response and mediate tissue injury.

Animals↗
PubMed1996

Polymorphonuclear neutrophils pulsed with synthetic peptides efficiently activate memory cytotoxic T lymphocytes.

Polymorphonuclear neutrophils (PMNs), traditionally considered effector cells in the inflammatory response, have recently been regarded as potential regulators of the immune response. In the present study we investigate whether PMNs are efficient antigen-presenting cells for reactivation of memory cytotoxic T lymphocytes (CTLs). PMNs were pulsed with synthetic peptides derived from Epstein-Barr virus (EBV) antigens. We have used the IVTDFSVIK (IVT) peptide derived from the Epstein-Barr virus-encoded nuclear antigen 4 protein, corresponding to the immunodominant epitope of HLA-AII-restricted CTL responses, and the CLGGLLTMV (CLG) peptide derived from the latent membrane protein 2 antigen, representing a subdominant epitope of HLA-A2-restricted CTL responses. The data indicate that peptide-pulsed PMNs selectively activate specific CTL responses to both immunodominant and subdominant epitopes. The efficiency of CTL induction by PMNs was comparable to that observed with the conventional method of EBV-specific CTL reactivation with the autologous lymphoblastoid cell line, as well as with peptide-pulsed monocyte-enriched adherent cells. On the contrary, unactivated peptide-pulsed lymphocytes failed to induce an epitope-specific CTL response. These results demonstrate that PMNs efficiently present antigens to memory virus-specific CTLs and suggest that they may have a role as antigen-presenting cells.

Amino Acid Sequence↗
PubMed1996

p53 exon 5 mutations in two cases of leukemic mantle cell lymphoma.

Although p53 mutations have been described frequently in high-grade B-cell non-Hodgkin's lymphoma (NHL), they have only been reported occasionally in low-grade NHL. We therefore describe clincobiologic and molecular genetic findings in two patients with p53 mutations and leukemic mantle cell lymphoma featuring an unusually aggressive course. Circulating malignant cells showed irregularity of nuclear outline with frequent deep clefts in both cases. Immunologic studies of neoplastic cells from peripheral blood samples and from cells obtained from an involved lymph node showed a mantle B-cell phenotype (CD5+, CD19+, CD22+, CD23- or weakly+ and bright expression for surface immunoglobulins). Malignant cells were shown to be hyperdiploid by cytofluorimetric study of DNA content and the presence of the t(11;14)(q13q32) was documented in one case. An altered electrophoretic mobility of p53 exon 5 was seen in both cases, with a missense mutation at codon 158 present in one case and a CAG to TAG mutation resulting in a 167-stop codon present in the second case. The percent of reactive cells with the 1801 monoclonal antibody detecting an epitope of the p53 was 37% in one case and 1% in the second case, supporting the notion that immunologic overexpression cannot be used for a selection criterion for the detection of p53 mutations. From these findings and from data available in the literature the conclusion can be drawn that p53 gene mutations at codons 158 and 167 may be associated with lymphoproliferative disorders and that low- or intermediate-grade NHL, including leukemic mantle cell lymphoma, may frequently carry this genetic change.

Aged↗
PubMed1996

[Pulse oximetry and methemoglobinemia].

BACKGROUND: Cyanosis associated to low oxygen saturation may reveal hemoglobin pathology. CASE REPORT: A 3 year-old child had a nephroblastoma with pleural effusion. He suddenly developed persistent cyanosis despite pleural effusion drainage; transcutaneous and measured oxygen saturations were low and PaO2 on arterial blood gases was high. Methemoglobinemia was diagnosed, due to prilocaine-lignocaine cream used for local anesthesia, associated to partial G6PD deficiency. The methemoglobinemia disappeared after methylene blue treatment. CONCLUSION: Cyanosis with low oxygen saturation and high or normal PaO2 should lead to the search of a hemoglobin pathology, especially methemoglobinemia, by appropriate methods.

Anesthetics, Local↗
PubMed1996

Richter's syndrome in a case of atypical chronic lymphocytic leukaemia with the t(11;14)(q13;q32): role for a p53 exon 7 gene mutation.

Clinicobiological, histological, cytogenetic and molecular genetic studies were performed in a case of atypical B-cell chronic lymphocytic leukaemia (B-CLL) with the t(11;14)(q13;q32) evolving into Richter's syndrome (RS) in order (a) to determine the clonal relationship between the cell of origin for B-CLL and RS, and (b) to analyse genetic events underlying the disease progression in this patient. After 4 years following diagnosis, a rapid deterioration of the clinical picture occurred, concomitant with the appearance of large lymphoid blasts in peripheral blood (PB), bone marrow (BM) and ascites samples. A diagnosis of RS was made and cytogenetic analysis revealed karyotype evolution with trisomy 7 and del(17p) in addition to t(11;14). Fluorescence in situ hybridization showed 78% lymphoid blast cells obtained from ascites sample to be trisomic using a chromosome-7-specific pericentromeric probe. Whereas no rearrangement of the c-myc proto-oncogene was detected at disease progression, direct sequencing of p53 gene exon 5-9 revealed an exon 7 missense point mutation. This abnormality was not present in the CLL phase. Immunological staining with the monoclonal antibody PAb-1801, detecting the p53 protein product, revealed a negative pattern in the CLL phase, whereas 24% positivity was documented in representative samples obtained at RS. It is concluded that RS was cytogenetically related with B-CLL in this patient, suggesting the occurrence of a bona fide transformation and that the mutation of p53 exon 7, in association with the development of 17p deletion, possibly played a role in the development of RS.

Aged↗
PubMed1996

Cellular dysmetabolism: the dark side of HIV-1 infection.

The progression to disease in subjects infected with the human immunodeficiency virus type I (HIV-1) cannot be explained solely on the basis of the infecting HIV-1 species. There is recent evidence that abnormalities in the cellular metabolism are crucial to the progression of the infection through common pathways that involve the induction of apoptosis and oxidant stress. Conversely, the low propensity of lymphocytes to undergo apoptosis, a normal redox status, and a balanced ceramide metabolism appear to predict a slow progression, or the non-progression at all, of the infection. It is likely that the ability of the host to maintain over time a balanced cellular metabolism despite the chronic infection with the virus contributes to the especially favourable outcome of an otherwise fatal infection seen in a discrete subgroup of HIV-1-infected individuals (long-term non-progressors) who might never experience any of the adverse effects of HIV-1 infection and will never demonstrate disease progression. Furthermore, this background supports the hypothesis that adjunctive therapies directed at correcting certain abnormalities of cellular metabolism seen in the infected host should be given in combination with antiretroviral drugs in order to slow the progression of the infection.

Acquired Immunodeficiency Syndrome↗